Synthesis Of Substitued Pyridine-2, 4(1H, 3H)-Diones From A-Acyl-A-Carbamoyl Ketene-S, S-Acetals

Synthesis of heterocyclics have been extensively investigated as medicine and versatile intermediates in the synthesis of multi-functional complex molecules and natural products. N-Substituted pyridone compounds have verastile physiological activity.For instance,they can sterilize,ease pain,resist tumour and cure parkinsonism and so forth.These compounds have powerful ability to form coordination compounds,which can cureβ-thalassemia beyond compare.The ramification of N-Substituted pyridone can be made to drug precursors.α-oxo ketene-S,S-acetals,which are first synthesis from 1885,have been proven to be useful in organic synthesis.Besides the use as thiol equivalents and an umpolung of the carbonyl group,the synthetic potential of dithioacetal functionality has been widely expanded in recent years.The former has provided effective method to avoiding thiols.For the recent decade,during the course of our studies on the chemistry ofα-oxo ketene-S,S-acetals,our group successfully developed novel strategies for the synthesis of highly substituted heterocycles,relying upon the utilization ofα-alkenoyl ketene-S,S-acetals.Combining with the special properties ofα-oxo ketenedithioacetals,we have succeeded in exploring a new kind of heterocycles.This work mainly based on the following three aspects:1.We enlarge the synthesis of 2-(1,3-dithiolan-2-ylidene)-3-oxo-N-phenylbutanamides, two newα-oxo-N-phenylbutanamides were synthesised.2.A facile and efficient one-pot synthesis of substituted pyridine-2,4(1H,3H)-diones has been developed.Subjected to N,N-dimethylformamide dimethyl acetal(DMFDMA) in DMF, a series ofα-acyl,α-carbamoyl ketene-S,S-acetals were converted into the corresponding substituted pyridine-2,4(1H,3H)-diones in high yields.The simple procedure,mild conditions,easy separation,high yields,and wide range of synthetic potential of the products make this protocol much attractive.So these new reagents have good perspective in the field of academic research and practical applications.3.We calculate the NBO state of(E)-5-(dimethylamino)-2-(1,3-dithiolan-2- ylidene)-3-oxo-N-phenylpent-4-enamide and it's negative ion by quantum chemistry method,and study the mechanism of the reaction acoording to the intermediate that we gain in the experiment.In summary,we have succeeded in exploring a new kind of N-Substituted pyridones, moreover,providing mechanism of the reaction by quantum chemistry method.This method is associated with some synthetic advantages,such as simple procedure,fast reaction rate, high yields,mild conditions and wide range of synthetic potential of the products make this protocol much attractive.So these new reagents have good perspective in the field of academic research and practical applications.